I've discovered, that above segfault exist only, when the physical link is active when the driver is loading. When the interfaces on the switch are disabled the driver loads successfully and both eth* are present. Some errors occurs when I enable interfaces on the switch on loaded driver:

finally we have changed X710 to X520-DA2 and it works ok. I don't know what was wrong with them. We experienced 2-3 situations when these adapters worked with full speed, but after reboot the problems appeard again.

NO worries and thank you for the clarification. Just to double check are you referring if you are using the validate fiber module on the X710-DA2 the same will occur? Are you going to use the X520 NIC instead, if that is the case any further assistance needed?

I don't have any module from supported module list, so I couldn't check that. I will not use X710 at the moment and I don't know if even in the future. If so, I'll let you know. For now you can close this topic.